The American Psychological Association
(APA) has endorsed gay marriage ahead of its annual convention in
Washington.

With a unanimous 157-0 vote, the APA's
policymaking body approved the resolution on Wednesday.

“Now as the country has really begun
to have experience with gay marriage, our position is much clearer
and more straightforward – that marriage equity is the policy that
the country should be moving toward,” Clinton Anderson, director of
APA's Office on Lesbian, Gay, Bisexual and Transgender Concerns, told
USA Today.

The resolution notes that many gay men
and lesbians “desire to form stable, long-lasting and committed
intimate relationships and are successful in doing so.” And adds
that campaigns to deny gay couples marriage equality “may have
negative effects on their psychological well-being.”

Evan Wolfson, president of Freedom to
Marry, cheered passage of the resolution.

“The American Psychological
Association represents over 100,000 medical professionals who see day
in and day out the real harms gay and lesbian people and their
families experience when denied the freedom to marry,” Wolfson said
in a statement. “With the freedom to marry in 12 countries on four
continents, and most recently New York joining 5 other states plus
the District of Columbia in ending exclusion from marriage, there is
a mountain of unrefuted evidence and experience showing that
extending the freedom to marry to loving, committed same-sex couples
helps them and their families while hurting no one.”

The APA has filed 11 amicus briefs in
support of marriage equality since approving a resolution on sexual
orientation and marriage in 2004.

In 2009, the APA approved a resolution
which repudiates “reparative” therapy, the controversial
gay-to-straight treatment also known as “pray away the gay.”